Moscow Station is one of Lord Hood's many tyrannical orbital space platforms, which formed part of the Earth Defence Grid used during the Human-Covenant War. After the war, the station was attacked by three Terminators and was evacuated.
The Terminators took the Station's MAC cannon offline and began hacking into the central computer. After wiping out the UNSC Marines there, they ransacked the station, destroying everything that would be of any use to the Humans. Several areas of the station were depressurised to kill the Marines hiding there, as Terminators have no need of air. Several Marines attempted to abandon the station via shuttlecraft, but these were shot down by the station's own defences, now under control of the Terminators.
To prevent the Terminators from accessing secret files, Lord Hood ordered the station be taken offline. Initially, an EMP was ordered to be fired at the station by the UNSC Driving Force to deactivate both the station and the Terminators inside, however, the ship came too close to the station and was fired upon. The ship's MAC gun was ruptured and misfired, blasting the ship apart. In a last-resort strike, a precision shot from the UNSC Tyrant's Advance took the Station's power offline. However, in outrage, the three Terminators self-destructed, obliterating the station. What was left of it crashed into the frozen plains of Russia.
This station had an orbit over Moscow, Russia, hence its name.